1. Field of Invention
This invention relates generally to flood control or hazardous liquid containment and specifically to a device to accomplish said control or containment.
2. Description of Prior Art
Whenever minor flooding occurs, it normally follows patterns of previous flooding. People respond to this with walls of sand bags placed in strategic places to divert or hold back flood water. In the case of hazardous liquid spills, special units of the fire department must depend on local material to fill sand bags wherever a spill occurs.
In either case, filled sand bags must be stored or sand kept handy for the filling of the bags or a suitable material must be found on site for the filling of the bags. Once the bags are filled, they must be transported from the fill site to where they will be used. This entails much labor involving stooping and bending increasing the risk of back injuries. This process is also slow, depending on how many people are available for the task. Heretofore, some solutions to this problem have been suggested.
One such device is a water-filled tube shaped like an equilateral triangle with an elaborate system of outside supporting members every foot or so to maintain its shape. The problem is the solid support members take up space and have weight that has to be transported. Also, there is labor involved setting up these supports and fastening them in place with an equal amount of labor involved in taking the device down.
The same problem exists for another device where the dam is simply a sheet of flexible film, making the attendant bracing necessarily heavier for support and stability.
Another way of addressing the problem is to replace the sand bag with another type of bag as in Bayer's device (4,650,368) wherein a water permeable bag of porous, absorbent material is used in place of sand bags. Being lighter than sand bags, they are easier to place, but no mention is made of drying, storage or disposal after they have absorbed water and done their job. Also, their permeability assures some leakage.
Another device is a bag to be filled with water instead of sand. Fitted with valves, cleats, special shapes and coverings, this device would be heavier than sand bags (more labor, more injury risk) while being much more expensive.
Brodersen's device (4,799,821) is more practical than the above but still leaves much to be desired. It consists of a plastic tube that assumes an oval shape when filled with water. It is tied in a knot at each end to keep water in. For one thing, it would seem to be difficult to introduce water into the device through an open end. The end would have to be elevated somehow, requiring one person to hold it while another introduces water into the opening. Also, tying a knot in a 7" diameter tube of 10 mil thick plastic may not be an effective way of sealing such a device. It would depend on the person's strength as to whether the device leaked or not. Also, the geometry of the filled tube is such that water would seep under it easier than under a triangular shape, necessitating some sort of sealing compound, as is pointed out, to be used to prevent leakage. This oval shape causes flood waters to exert minimal downward force compared to lateral forces, creating an instability in location of the device during service. Therefore, this device would work better if a heavier fluid than that it is to contain or divert is used to fill it. Once filled, the knot in each end makes it difficult to seal the ends against themselves or other objects. The invention described herein will obviate the described disadvantages of previous solutions and proposed solutions to flood control and/or hazardous liquid spill containment.